Schematic diagram of the integrated self-powered system. (a) |
Scientists
are reporting development of the first self-powered nano-device that
can transmit data wirelessly over long distances. In a study in ACS’s
journal Nano Letters, they say it proves the feasibility of a futuristic
genre of tiny implantable medical sensors, airborne and stationary
surveillance cameras and sensors, wearable personal electronics, and
other devices that operate independently without batteries on energy
collected from the environment.
Zhong
Lin Wang and colleagues explain that advances in electronics have
opened the door to developing tiny devices that operate battery-free on
minute amounts of electricity that can be harvested from the pulse of a
blood vessel, a gentle breeze, or the motions of a person walking. “It
is entirely possible to drive the devices by scavenging energy from
sources in the environment such as gentle airflow, vibration, sonic
wave, solar, chemical, and/or thermal energy,” the scientists explain.
The
device consists of a nanogenerator that produces electricity from
mechanical vibration/triggering, a capacitor to store the energy, and
electronics that include a sensor and a radio transmitter similar to
those in Bluetooth mobile phone headsets. Their device transmitted
wireless signals that could be detected by an ordinary commercial radio
at distances of more than 30 feet.
Study abstract: “Self-Powered System with Wireless Data Transmission”
We
demonstrate the first self-powered system driven by a nanogenerator
(NG) that works wirelessly and independently for long-distance data
transmission. The NG was made of a free cantilever beam that consisted
of a five-layer structure: a flexible polymer substrate, ZnO nanowire
textured films on its top and bottom surfaces, and electrodes on the
surfaces. When it was strained to 0.12% at a strain rate of 3.56% S–1,
the measured output voltage reached 10 V, and the output current
exceeded 0.6 ?A (corresponding power density 10 mW/cm3). A system was
built up by integrating a NG, rectification circuit, capacitor for
energy storage, sensor, and RF data transmitter. Wireless signals sent
out by the system were detected by a commercial radio at a distance of
5–10 m. This study proves the feasibility of using ZnO nanowire NGs for
building self-powered systems, and its potential application in wireless
biosensing, environmental/infrastructure monitoring, sensor networks,
personal electronics, and even national security.
SOURCE: American Chemical Society
